It's not what you think. Scottsdale resident Mitch Stanley knows what the March 13 "UFO" was. But will anyone listen?

Grava says that depending on the planes' altitude, that may have been perfectly legal.

But whose planes were they? Sightings place the group north of Prescott about 8:15 and south of Tucson by 8:45. That's 200 miles in 30 minutes, which suggests an air speed of 400 miles per hour. Many witnesses swear that the group was moving slowly and was near to the ground, perhaps as low as 1,000 feet. But from the ground, such naked-eye estimations--particularly of shapeless lights--are unreliable. If the group seemed to go only 50 miles per hour when it was really going about 400 mph, the group must have been very high indeed. Such is the stuff of simple physics. Some quick trigonometry based on Holthouse's memory of the group's angular speed suggests a height of 6,000 feet. Other witnesses claim that the group seemed so slow as to have almost no angular speed, which suggests a much higher altitude (and might explain why no sound was heard on the ground).

Mitch Stanley's sighting jibes well with witness reports that the configuration of the lights changed over time. In Prescott, for example, witnesses claim that one of the lights trailed the rest. Such evidence supports the claim that the lights were separate objects rather than one large craft.

Pilots consulted by New Times say that a group of planes flying in formation at night suggests military aircraft. The squarish wings, as opposed to the swept, triangular variety, suggest A-10s or T-37 fighter-trainers.

Among the rumors making the rounds in commercial aviation: that the group was the Canadian Snowbirds, a group of T-37s which flies at air shows. A spokesman for the Snowbirds says their season does not begin until April, however, and that the troupe was not in Arizona in March. New Times has contacted numerous military bases in the Southwest, but none claims the planes.

All witnesses seem in agreement on one thing: the unusual brightness of the lights. Flight controller Grava says that's the only reason he is reluctant to accept the explanation that it was a group of airplanes that flew over Arizona March 13.

Until a group comes forward to claim the flight, however, the planes' unusual lights and apparent lack of transponder signals suggest the possibility of a calculated hoax.